Dental-engine hand-piece



(No Model.) 2 Sheets-Sheet 1. S. H. BROOKS. DENTAL ENGINE EAND PIECE.

Patented Sept. 12

2 Sheets-Sheet 2.

s. ELl BROOKS. DENTAL 'ENGINE HAND PIECE.

Patented Sept. 12, 1893,

(No Model.)

UNrrnn STATES ff Y.

STEPHEN II. BROOKS, OF RROOKLYN, NEW YORK, ASSIGNOR TO THE IVIL- MINGTON DENTAL MANUFACTURING COMPANY, OE IVILMINGTON, DEL A" IVARE, NEIV YORK, N. Y., AND PHILADELPHIA, PENNSYLVANIA.

Parana* -rrrca DENTAL-ENGINE HAND-PiECE.

SPECIFICATION forming part of Letters Patent No. 504,704, dated September 12, 1893.

Application iiled February 5, 1892. Serial No. 420,448. (No model.)

To @ZZ 1071/0712, it may concern:

Be it known that I, STEPHEN H. BROOKS, a citizen of the United States, and a resident of the city of Brooklyn, county of Kings,in the State of New York, have invented a certain new and useful Improvement in Dental-Engine Hand-Pieces, of which the following` is a specification.

My invention has relation to dental engine hand pieces, and more particularly to that class of hand pieces in which the operator may by asingle movement stop the rotation of the burr or tool without interfering with the driving power, and also unlock and disengage the mechanism which secured the said burr inside the tool holder.

In the accompanying drawings forming a part of this specification, Figure 1, is a side elevation of myimproved hand piece, the tool or burr being secured in place. Eig. 2, is a sectional view of the same. Fig. 3, is a side elevation of my improved hand piece, showing the position the outer casing assumes before a tool is locked in place, or after it has been unlocked. Fig. e, is a sectional view of the parts in the position described in Fig. 3. Fig. 5, is a perspective view of the various parts of the hand piece separated and arrangedin juxtaposition. Fig. 6,is asectional view of the saddle. Fig. 7, is a view of the chuck preferably employed in my hand piece.

In the drawings the numeral 1, indicates the outer casing of my hand piece. 2, is the inner rotary tubular shaft having a reduced end 2a provided with a longitudinal slot 3, for a portion of its length, and having recesses a, e therein, for the reception of the supporting portions of the toggle lever to be hereinafter described.

In the nose portion 7, of the inner rotary tubular shaft 2, is inserted a chuck 8, of any suitable construction. This chuck is caused to engage the shank ol' the tool by means of a cylindrical block 9, havingr a tapering recess at one end adapted to ride over the tapering jaws at the inner end of the chuck and so force Ithe chuck forward into engagement with the nose of the tubular shell.

Adapted to operate directly against the inner end of the cylindrical block 9, is a bearing 10, provided with ears 11. This bearing is adapted to slide in the hollowed portion of the rotary shaft 2, and has a concaved recess 12, in its end to receive the rounded end of one member 13, of the toggle lever. As is obvious the bearing 10 may be dispensed with by providing the block 9 at its rear portion with a concaved recess, adapted to receive the end of the member 13 of the toggle lever.

The toggle lever preferably consists of the two members 13 and 14. Both ends of the member 13, are rounded, one of said rounded ends, as already described, tting in the concave in the bearing 10, andthe other rounded end fitting in a corresponding recess 15, in the larger member 14, of said lever. Said larger member is provided with a supporting saddle 16, 16, which fits in the recesses A, A, of the rotary tubular shaft 2. Inwardly from said saddle the member 14e, is preferably curved, and is also preferably elastic, and provided with a heel piece 17.

I will now describe what may be termed the second or rear section of my dental engine hand piece.

The rear portion 1S, of said second section 19, is adapted to be connected to the covering of the iieXible driving shaft 20, in any suitable manner.

Extending forwardly from said rear portion 1S, is a shaft 21, the forward extremity 22, of which has a flexible connection,as at 23, with a lever 24C, adapted to actuate the toggle lever 13, le, and through the latter the chuck. The lever 2i, has a shoulder 25, from where it tapers forwardly, and at its tapered end 26, is provided with a toe 27, at the side 0f the lever opposite the shoulder 25.

On the shaft 21, is located a collar or boss 2S, which acts as a stop for a sleeve 29, which loosely slides over the said rod 2l, and lever 24C. Said sleeve is provided at one end with a threaded collar 80, adapted to be connected to portion 1S, which is coupled to the covering of the iiexible driving shaft. The sleeve 29, is provided in its outer side with a longitudinal groove 3l, for a purpose to be hereinafter described.

.as shown in Fig. 2.

ver,v the sleeve 29, I also place a short sleeve 32, threaded externall;7 and internally and provided on its inner side with a spline 33,adapted to engage the groove 3l, in the sleeve Another sleeve 34, screws into the said short sleeve 32, and is provided with adjusting means preferably consisting of a split nut 35. The external thread of the sleeve 32, is for the purpose of receiving the threaded end of the casing l.

To secure a tool or burr in the chuck of the holder the shank of the tool is simply placed in the opening ofthe nose-piece, it being presumed that the parts are in their retracted positions, (see Figs. 3 and 4.) This being the case, the collar 30, of the sleeve 29, is in its rearward position, resting against the boss 28, the covering of the flexible shaft being secured to said collarand bearing against the outer end of said stop. Aslight push by the fingers of the operator will move forward the collar 30, and the tool or burr is thereby caused to be rigidly clamped and held by the chuck. The operation resulting from said forward movement of the collar is as follows, the parts being assembled as shown in the longitudinal sectional view in Fig. 4:- The forward movement of the shafting and covering and the stop 2S, causes the rod 2l, and lever 24, to move in the same direction, `the movement of the lever being guided by the toe-piece 27, engaging the walls of the slot 3. In sliding forward the portion 26, of the lever 24, engages the heel piece I7, of the toggle member 14, thus depressing it and oscillating it on its supports 16, 16. The rocking of the member 14, causes the member 13, to straighten, and to thus force forwardly the saddle l0, and the block 9. The recessed tapered portion of the forward end of block 9, rides over the correspondingly tapered portion of the inner end of the chuck 8, forcing said chuck forward into the contracted portion of the nose, thereby clamping the tool The tool is as readily released, it being merely necessary to give a slight rearward movement to the collar 30, when the resiliency of the parts willinstantly allow a rearward movement of the block 9, and the opening of the chuck jaws.

Motion is imparted to the tool orburr when it is clamped by the chuck through the medium of the ordinary flexible shafting used in dental engines, the covering of the said shafting being secured to the hand piece at 1S.

Experience has shown that with my new hand piece tools with smooth or any other form of shank may be instantaneously secured and rigidly held in position. I thus dispense with the expensive labor necessary in preparing special forms of shanks for dental tools.

The preferred form of chuck employed by me is that illustrated in Fig. 7. This chuck is produced as follows: I take a blank, half the desired length of the finished chuck, and cut or ream out the superfluous metal about the center thereof, and taper one end thereof, the other end being left straight or pla I may bore the blank either before or after the steps already mentioned. The blank is then split longitudinally in the ordinary manner. Two of the half length chucks 36 and 37, are then placed with their butt-ends together, and the entire chuck is completed. The advantages of making a chuck in this manner, and of the completed chuck are that the metal blank is much more conveniently handled; that many small pieces of material may be utilized; that the parts are not so likely to be damaged by the operatiomwhile if one end of the chuck becomes damaged or breaks it is not necessary to discard an entire chuck, as a new end piece may be readily substituted for the damaged portion, both ends, as already intimated, being duplicates.

Among the advantages of my dental hand piece are its simplicity of construction, its non-liability to get out of order, its compactness, and the ease with which its various parts may be separated.

What I claim is* l. A dental hand piece comprisinga chuck, a block for engaging the inner end thereof and a toggle lever for operating said block, substantially as and for the purpose specified.

2. A dental hand piece comprising a chuck, a block for engaging the inner end thereof, a bearing against said block, and an oscillating toggle lever substantially as and for the purpose specified.

3. A dental hand piece comprising a chuck, a block for engaging the inner end thereof, a movable bearing abutting against said block, an oscillating toggle lever and a lever for operating said toggle lever substantially as and for the purpose specified.

4. A dental hand piece comprising a chuck, a block for engaging the inner end thereof, a toggle lever engaging the block, and a lever for operating the toggle substantially as and for the purpose specified.

5. A dental hand piece comprising a chuck, a block for engaging the inner end thereof, a toggle lever, a lever for operating the latter, a driving shaft and a iiexible connection between the lever and the driving shaft substantially as and for the purpose specified.

6. Adental engine hand piece, comprisinga casing, a slotted tubular rotary shaft within the casing, a toggle having bearings in said shaft, and a lever guided by the slot in said shaft, and means for operating the lever substantially as and for the purpose specified.

7. A dental engine hand piece comprising a casing, a slotted tubular shaft, a toggle lever provided with a heel piece having bearings in the slot in said shaft, a lever guided by said slot, and provided with a shoulder bearing upon the heel piece of the toggle lever substantially as and for the purpose specified.

IOO

S. A dental engine hand piece, provided with a easing, a slotted tubular rotary shaft, a ehuek, a block adapted to engage the chuck, a toggle lever for operating the chuck, a lever in engagement with the latter, a drivngshafb, a yielding Connection between the two last mentioned elements, a grooved sleeve inclosing the driving shaft and lever, a splined sleeve tting over the last mentioned sleeve, and n sleeve 3%, extending forwardly from the spline sleeve, and means for the longitudinal 

